Which of the following waves is not same as others?

Options

A. Sound waves
B. Waves on the surface of water
C. Waves on strings
D. Radio waves

Explanation

To determine which of the following waves is not the same as the others, we will analyze each wave type provided in the question.

### Step-by-Step Solution:

1. **Identify the Types of Waves:**
- We have four types of waves to consider: sound waves, waves on the surface of water, waves on a string, and radio waves.

2. **Analyze Sound Waves:**
- Sound waves are classified as **longitudinal waves**. In longitudinal waves, the oscillation of particles occurs in the same direction as the wave propagation. This means that when sound travels, the air particles move back and forth in the same direction as the sound wave.

3. **Analyze Waves on the Surface of Water:**
- Waves on the surface of water are classified as **transverse waves**. In transverse waves, the oscillation of particles is perpendicular to the direction of wave propagation. When a stone is thrown into water, the ripples move outward while the water particles move up and down.

4. **Analyze Waves on a String:**
- Waves on a string are also **transverse waves**. When a string is plucked, the disturbance travels along the string while the particles of the string move up and down, which is perpendicular to the direction of the wave.

5. **Analyze Radio Waves:**
- Radio waves are classified as **electromagnetic waves**. They are also transverse waves, but they are fundamentally different from mechanical waves (like sound, water, and string waves) because they do not require a medium to propagate. They can travel through a vacuum.

6. **Conclusion:**
- Among the four types of waves, sound waves are the only **longitudinal waves**, while the other three (waves on water, waves on a string, and radio waves) are transverse waves. Therefore, the wave that is not the same as the others is the **sound wave**.

### Final Answer:
The wave that is not the same as the others is the **sound wave**.

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